Improvement in recording pressure-gages



UNITED STATES PATENT OEEIGE.

JARVIS B. EDSON, OF BROOKLYN, NEW YORK.

IMPROVEMENT IN yRECORDING PRESSURE-GAGES.

Specification forming part of Letters Patent No. 106,345, dated-August16, 1870.

To all whom fit may concern:

` Beit known that I, Jnavrs B. ED'soN, of Brooklyn, Kings county, NewYork, have invented new and useful Improvements in the Construction ofRecording Pressure-Gages; and that the following is a full and exactdescription of the same, reference being had to the drawing accompanyingand making part of this my specification.

The object of these improvements is to ascertain and mark the extent andvariations of pressure in steam-boilers, steam-cylinders, or any othervessels containing air, gas, or liquids under pressure by delineationsupon a chart, either operated automatically by the pressure to b emeasured or driven by gearing from an engine.

My invention consists, first, in a new man- I n'er of constructing andarranging diaphragm elastic spings or chambers, in which the pressureacts; secondly, in the mechanical devices by which the action of thesprings is adapted to recording the pressure separately or in connectionwith the motion of an engine by lines upon the moving chart.

' In the accompanying drawing, Figure l represents a front elevation ofthe instrument, a portion of the same being removed to show the interiorparts. Fig. 2 represents a top view of the same. n

Similar letters represent similar parts of the figures in the drawing.

The first part of my invention, which has reference to the means bywhich the pressure is received, and thereby communicates the desiredmovement to the instrument, consists in the new manner of constructingand arranging the diaphragm-springs. These springs consist of a seriesof cireularelastic chambers. They are composed of thin steel circulardisks, with or without corrugations, each pair forming a separatechamber, by means of a iiat brass or composition ring, interposedbetween thin outer edges, and two compressing-rings, above and under theinterposing ring, and which are secured together by screws or anysuitable fastenings, so as to be steam and airtight. I

The elastic chambers are shown in Fig. 1 in section, the pairs ofelastic plates at a, the intermediate separating-ring at b, and thecompressin g-rin g at c.

The chambers are connected together by a hollow connection, secured tothe centers of the plates around an opening, and they are provided withalternate male and female screwthreads, so as to be connected togetherin a series, the joints being steam and air tight. rPhesescrew-connections are shown at Fig. l at d.

The lower chamber is secured to the bedplate, and is provided with acoupling, d, by which conn-*ction is made, through a suitable pipe, witha boiler or other reservoir containing the pressure. The upper chamberhas on the top plate a short fixed vertical stud, d. These chambers areplaced in a suitable frame or casing, e, of brass or other material,which forms a bearing for the operating mechanism,

and is secured by screws through a flange at the base to the bed-platef.

The second part of my invention applies to the mechanism for operatingthe moving chart and recording-pencil or tracing-point, and isconstructed as follows: Upon a suitable bearing, G, on the upper part offrame E, is the segmental rack h, oscillating vertically on the pivotsfi, and having on its outer segmental periphery teeth which gear intothe pinion j, fast to the horizontal shaft 7c, on the front end of whichis xed the spur-wheel l, and on the opposite endthe smaller spur-wheelm, which gears into the horizontal sliding rack N, which, passingthrough slots in the frame E, extends outside the same in oppositedirections.

Upon the side of the segmental rack h is fixed the open rectangularframe or shoulder O, within which is arranged the sliding adj ustablelink p, and which is made to slide toward or from the center ofoscillation of the segmental rack h by means of the two adjusting-screwsat the opposite ends, the points of which work in suitable sockets inthe link p.

The connecting-rod a2 is, at its upper end,

pivoted upon a pin fast in the link p, and at its lower end is fastenedby a pin to the stud d2. The use of the sliding link p is to increase ordimish the extent of oscillation of the segmental rack It and the rangeof the parts which it puts in operation.

R is a reservoir-drum, upon which the paper chart is wound. Its bearingsare upon conical points in corresponding sockets in the cen ter ofthedrum-heads, the lower being fixed in the bed-plate, the upper bearingbeing an adjustable thumb screw, frl, whichpasses through the horizontalbracket r2, attached to the back of the frame of the instrument.

Upon the opposite side of cylindrical casing c is the receiving-drum S,which has its lower bearing similar to that of drum It, and above in araised bearing on the top of the drumhead. These drums have a narrowslot passing through their length, into which is iitted aneccentric-rod, so as to hold the paper and prevent its slipping, asshown at S1, Fig. 2.

Around the edge of the upper head of drum S is a raised rim, makingwithin a hollow circular space, in which is placed the universal pawl t,which is centered upon the central bearing t1, fast upon the drum-head.

The short arm t2 of the pawl t is so eccentrically arranged that itsouter end will, when the pawl is pushed forward, always catch upon theinner surface 0f the raised rim on the drum-head, and thus producerotary movement to the drum S, while the movement of the pawl backwardin the opposite direction does not produce any motion of the drum, thearm t2 sliding backward without producing any impingement upon the rim.

The additional pawl u is provided as a brake, to prevent the recoil ofthe drum. The pawl t is operated at its outer end by the fixed pin inthe end of horizontal rack n. The paper chart, of any desired length,wound around the drum It, is passed in front of the bearing on thecasing E, and thence to the receivingdrum S, after receiving thedelineation of the pencil. i

The paper chart is shown in Fig. 2 at c, and moves in the directionindicated by the arrows, and it is also shown in Fig. l on both thedrums, and on the part of Fig. l which shows the removed portion of Fig.l, the chart being marked with graduated horizontal parallel lines,figured so as to show the degree of pressure.

In front of the cylindrical shell E is the vertically-slidin g rack w,in suitable bearings upon E, the teeth of the rack w meshing into thoseof the spur-wheel b, above described, and by which the rack is operated.A

In front of the rack w, and parallel with it, is the springlpencil-holder which is joined at its upper end to projecting stud fastupon the rack w, and lis pressed inward by the spring, thus keeping thepencil close upon the chart, which moves between it and the bearing uponthe frame E.

The operation of the above-described apparatus is as follows: Pressurefrom the steamboiler or other vessel sustaining pressure beingintroduced into the diaphragm-chambers through the coupling d1, theplatesexpand and raise the rod a2 on the upper plate of the topmostchamber. This upward movement raises the segmental rack, which, at thesame time, receiving-drum S, and, by its connection with the pawl t, thereverse movement of the rack, caused by decrease of pressure, rotatesthe drum S. A A

When the tracings are to be upon unsized paper, the pencil may be oflead; but when cards are to be taken on what is called metallic paper,77for any specific purpose, a metallic point must be used in a holderadapted to the purpose. These tracin gs will be, as shown, of verticaland oblique lines; but when drum S is operated by gearing from anengine, the delineations will not be conned to vertical and obliquelines, but more continuous.

I connect an alarm apparatus with the abovedescribed mechanism, for thepurpose of giving notice when any determined limit of pressure isreached. f

The hammer of the alarm apparatus is shown at I, and the bell or gong 2is placed over the cylindrical casing E. The tripping of the hammeris-produced by the action of a pin in the end of the racky n, which isset in the rack so as to be adjustable at any point in the movement ofthe rack, which will give the alarm at high pressure.

By the operation of my improvements and invention, as above described,awritten record, which is unerring and continual, is producedautomatically, showing the pressure and changes of pressure within asteam-boiler or other vessel sustainir. g pressure, and which recordsare valuable and useful, as well for scientific as for practicalpurposes; and the apparatus is made to give an alarm when the pressurehas arrived at a point to be dangerous, the tendency of this recordinginstrument being to prompt all in charge of boilers to a more faithfulperformance of duty, whereby greater safety to life and property issecured.

This apparatus, being compactlyarranged, is inclosedin a metal box,having a glass in front, through which the tracings may be observed, andwhich case or box may be locked, when desired, for particular purposes.

Having thus described my improvements and the construction and operationof the same, what l claim therein as my invention, and for which Idesire Letters Patent, is as follows:

1. The combination of the springs aa a, the connected rod a2, theoscillating segmental rack h, the adjustable sliding link p, the pinionj, the shaft k, the spur-wheels l and m, for operating the racks w andn, the paper-carrying-drums R and S, and the alarm-movements l and 5with the spring recordingpencil X, as shown and described, whether putin motion by any fluid or liquid under pressure, or in part operated bygearing to an engine.

2. The cylindrical frame (inclosing the I carries the rack a in thedirection of the springs) and its interior bridge g, which af- While thefront of said frame E affords a suitafords a rm and substantial bearingfor the ble bearing for the rack w and Jche paper segmental rack h,supporting the adjustable chart when receiving records or delineationslink p, to which the upper end of the connectof pressure.

ing-rod. a2 is attached, and upon which it de- JARVIS B. EDSON. pendsfor support, and. to protect the spring- Witnesses: connections frominjury and. vbratorystrain M. B. EDSON,

from the constant jarring of a locomotive, CHARLES NETTLETON.

